1. Field of the Invention
The present invention relates to a resin composition. Specifically, the present invention relates to an epoxy resin composition containing a melamine compound as a hardener, and a prepreg and laminate prepared using the same.
2. Descriptions of the Related Art
Printed circuit boards (PCBs) are circuit substrates that are used for electronic devices to load other electronic components and to electrically connect the components to provide a stable circuit working environment. One kind of a conventional printed circuit board is a copper clad laminate (CCL), which is primarily composed of resin(s), substrate(s) such as reinforcing material(s) and copper foil(s). Conventional resins include such as epoxy resins, novolac resins, polyamine formaldehyde resins, silicone resins or polytetrafluoroethylene resins; and conventional reinforcing materials include such as glass fiber cloths, glass fiber mats, insulating papers or linen cloths.
Considering the subsequent electronic processes, properties such as heat resistance, size stability, chemical stability, workability, toughness, and mechanical strength, etc. should be taken into consideration during the preparation of the printed circuit board. Generally, printed circuit broads prepared by using an epoxy resin can properly meet the above requirements. Hence, epoxy resins are those most commonly used in this field. However, printed circuit broads prepared by using an epoxy resin are usually provided with a high dielectric constant (Dk) value and a high dissipation factor (Df) value, which are disadvantageous for signal transmission. Specifically, because the signal transmission rate is in inverse proportion to the square root of Dk, the higher the Dk value, the lower the signal transmission rate; and due to the material resistance, the higher the Df value the higher the signal lost in the laminate. Therefore, the industry is committed to provide a laminate with good physicochemical properties and low Dk and Df values.
It is known that N,O-heterocyclic compounds with a
structure can be used as a hardener to regulate epoxy resin. Due to the high proportion of benzene rings and C—N bonds in the structure, the N,O-heterocyclic compounds possess excellent physicochemical properties (such as a good thermal resistance, a high glass transition temperature, an outstanding flammability and a good solubility for organic solvents). In addition, the polymer prepared from a ring-opening polymerization of N,O-heterocyclic compounds has a large number of hydroxyl groups in its structure and can further react with an epoxy resin to provide a final product with improved thermal and mechanical properties. For example, U.S. Pat. No. 7,781,561 discloses a method for manufacturing an N,O-heterocyclic compound with a
structure, wherein a melamine compound with three
structures is synthesized with the utilization of a melamine.
The present invention provides a resin composition for preparing a laminate. The resin composition has a good solubility for organic solvents and thus, is convenient for application. The laminate prepared using the resin composition is provided with outstanding physicochemical properties (such as a high glass transition temperature, a good moisture resistance, a low coefficient of thermal expansion, and a good solubility for organic solvents), and electrical properties (low Df and Dk values).